JP3192186B2 - Zirconium compounds having asymmetric ligands and catalyst components - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel zirconium compound having a bridging ligand having an asymmetric substituent. The compound of the present invention is effective as a catalyst component for stereoregular olefin polymerization.

[0002]

2. Description of the Related Art Kaminski catalysts (metallocene / methylalumoxane) are widely known as homogeneous catalysts for olefin polymerization. This catalyst system is characterized by a remarkably high activity per transition metal. Recently, it has been known that stereospecific polymerization is possible in the polymerization of α-olefins (mainly propylene). For example, atactic polypropylene (Makromol. Chem., Rapid Com.
mun. 4, 417-421 (1983), JP-A-58-19309), isotactic polypropylene (Angew. Chem. Int. Ed.
Engl., 24, 507-508 (1983), J. Am. Chem. Soc., 106, 6355 (198
4), J. Am. Chem. Scc., 109, 6544 (1987), Chem. Lett., 1853-1.
856 (1989), JP-A-2-76887)), syndiotactic polypropylene (J. Am. Chem. Soc., 110, 6255, (198)
8)) and the like can be produced. The key to the expression of these stereospecificities is the ligand structure and the stereostructure of the zirconium complex. However, zirconium compounds that can produce industrially important isotactic polypropylene include Et (Ind) 2ZrCl2 and Me2Si (2,3,5-Me3C
There are only C2 symmetries in the molecule, such as 5H) (2 ', 4', 5'-Me3C5H) ZrCl2, and the resulting polymer does not have sufficient stereospecificity. Was extremely difficult to purify.

[0003]

The problem to be solved by the present invention is to synthesize a novel zirconium compound which does not cause the problems in the prior art as described above, and to provide a useful catalyst component for stereospecific olefin polymerization. It is to provide.

[0004]

Means for Solving the Problems The present inventors have made intensive studies to solve the above problems, and as a result, have succeeded in efficiently synthesizing the following novel zirconium compounds, and The present inventors have found that the compound is useful as a catalyst component for stereospecific olefin polymerization, and have completed the present invention. That is, a non-C2 symmetric zirconium compound having an asymmetric ligand represented by the general formula (1).

Embedded image [In the formula (1), X ¹ and X ² may be the same or different and each represent a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, an alkylsilyl group, or a halogen atom.
R ¹ represents a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms or an alkylsilyl group, and one of R ² and R ³ represents a hydrocarbon group or an alkylsilyl group having 1 to 10 carbon atoms, The other means a hydrogen atom. R ⁴ represents a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms or an alkylsilyl group. And the catalyst component for olefin polymerization containing this compound as an active ingredient.

Hereinafter, the present invention will be described in detail. The zirconium compound defined by the formula (1) is a novel zirconium compound having a bridging ligand having an asymmetric substituent.
One of the substituents R ² and R ³ at the position specified in the formula (1) on the cyclopentadienyl ring of the zirconium compound of the present invention is preferably a hydrocarbon group having 1 to 10 carbon atoms (alkyl, Aryl, alkylaryl, arylalkyl, etc.) or alkylsilyl group (trialkylsilyl group, triarylsilyl group, etc.), more preferably a bulky substituent such as tert-butyl group. It is. However, one of R ² and R ³ needs to be a hydrogen atom.

Representative synthetic route for compound (1) of the present invention
Is abbreviated as follows, but is limited by this
Not. C₉H₈(Indene) + BuLi + tBuBr --- tBu-C₉  H₇  tBu-C₉H₇+ BuLi + tBu-C₅H₃= C (CH₃)₂  −−−− → (CH₃)₂C (tBu-C₅H₄) (TBu-C₉H₆) (CH₃)₂C (tBu-C₅H₄) (TBu-C₉H₆) + 2BuLi −−−− → Li₂[IPr (tBu-C₅H₃) (TBu-C₉H₅)] Li₂[IPr (tBu-C₅H₃) (TBu-C₉H₅)] + ZrCl₄  −−− → iPr (tBu-C₅H₃) (TBu-C₉H₅) ZrCl₂

[0007] A method for producing a bis-substituted cyclopentadienyl bridge type bidentate ligand having a crosslinked structure is known. That is, J.I. Am. Chem. Soc. , 110,976-97
8 (1988); Am. Chem. Soc. , 10
7, 8103-8110 (1985).
Such a bidentate ligand can be lithiated with an alkyl lithium to form a lithium compound, and then a zirconium halide Z
It can be obtained by reacting rX ₄ (X is a halogen atom). Instead of a lithium compound, a potassium or sodium compound may be used. The reaction between ZrX ₄ and a lithium compound can be carried out using ethers, preferably tetrahydrofuran, as a reaction solvent. More preferably, the reaction can be carried out at -78 ° C using methylene chloride as a reaction solvent. The reaction is preferably carried out at a molar ratio of lithium compound to ZrX ₄ in the range of 1.0 to 1.5, especially 1.0 to 1.1. The reaction temperature is from -80 ° C to 100 ° C, especially -2
A range from 0 ° C to 40 ° C is preferred. The generated zirconium compound can be purified by recrystallization. As an example of the zirconium compound, isopropylidene (3-
Methyl-cyclopentadienyl) (3-methyl-indenyl) zirconium dichloride, isopropylidene (3
-Tbutyl-cyclopentadienyl) (3-methyl-indenyl) zirconium dichloride, isopropylidene (3-tbutyl-cyclopentadienyl) (3-tbutyl-indenyl) zirconium dichloride, isopropylidene (3-methyl- Cyclopentadienyl) (3-methyl-indenyl) zirconium dimethyl, isopropylidene (3-tbutyl-cyclopentadienyl) (3-
Methyl-indenyl) zirconium dimethyl, isopropylidene (3-tbutyl-cyclopentadienyl) (3
-Tbutyl-indenyl) zirconium dimethyl.

The zirconium compound according to the present invention exhibits excellent olefin polymerization activity in the presence of aluminoxane or in the presence of a quaternary boron anion which effectively stabilizes the Zr cation, and is a compound useful as a polymerization catalyst component. is there. Aluminoxane as another catalyst component used in the polymerization is an organoaluminum compound represented by the general formula (2) or (3).

Embedded image

Embedded image In the above formula, R ⁵ represents a methyl group, an ethyl group, a propyl group,
It is a hydrocarbon group such as a butyl group and an isobutyl group, and is preferably a methyl group. m is an integer of 4 to 100, preferably 6 or more, especially 10 or more. The production method of this kind of compound is known, and for example, a method of adding a trialkylaluminum to a hydrocarbon solvent suspension of a salt having water of crystallization (copper sulfate hydrate, aluminum sulfate hydrate) is exemplified. I can do it.

In the method of the present invention, the olefin used for the polymerization is ethylene, propylene, 1-butene, 2-olefin.
Examples include olefins such as butene, 1-pentene, 4-methyl-1-pentene, cyclopentene, norbornene, cyclopentadiene, butadiene, 1,5-hexadiene, and 1,4-hexadiene, cyclic olefins, and dienes. I can do it. It is also possible to polymerize a mixture of two or more of these components. The polymerization method used in the present invention can be either liquid phase polymerization or gas phase polymerization. Solvents for liquid phase polymerization are hydrocarbon compounds capable of dissolving both zirconium compounds and aluminoxane components, such as benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, butylbenzene, mesitylene, chlorobenzene, etc. Are used, and toluene and xylene are preferable.

The zirconium compound of the present invention comprises silica,
It can be used in a solvent or monomer in which both the zirconium compound and the aluminoxane cannot be dissolved by being supported on a carrier such as alumina or magnesium chloride or by prepolymerizing an olefin. As the catalyst component, a mixture of both components of the zirconium compound and the aluminoxane in advance may be supplied to the reaction system, or both components may be supplied to the reaction system. In any case, the molar concentration ratio of both components in the polymerization system is not particularly limited, but preferably, Zr
Concentration of 10 ⁻³ to 10 ⁻¹⁰ mol / l, and Al / Z
The molar ratio of r is preferably used in the range of 10 or more, particularly 100 or more. The olefin pressure of the reaction system is not particularly limited, but is preferably from normal pressure to 50 kg / cm ² G
The polymerization temperature is not limited, but is preferably in the range of −30 ° C. to 100 ° C. The molecular weight at the time of polymerization can be adjusted by known means, for example, by selecting a temperature or introducing hydrogen.

[0011]

Next, the present invention will be described specifically with reference to examples. The analytical instruments used for measuring the physical properties are as follows. ¹ H-NMR JEOL EX-400 mass spectrometer JEOL JMS-AX500 IR PerkinElmer 5150 Example 1 [Isopropylidene (3-tbutyl-cyclopentadienyl) (3-tbutylindenyl) zirconium Dichloride] The reactions were all performed in an inert gas atmosphere. Also,
The reaction vessel used was previously dried. 30
100 ml of dry THF was charged into a 0 ml glass reaction vessel, 3 g of dimethyl (3-tbutylcyclopentadienyl) (3-tbutylindenyl) methane was dissolved therein, and 15 ml of a 1.6 Mn-BuLi hexane solution was ice-cooled. Added below. After reacting at room temperature for 1 hour, THF was distilled off under reduced pressure. While cooling, 50 ml of methylene chloride
Was added. 2.63 g of zirconium tetrachloride was charged into a separately prepared flask, and 50 ml of methylene chloride was added.
Was added and suspended. This is cooled and the dimethyl (3-t
A suspension of the lithium salt of butylcyclopentadienyl) (3-tbutylindenyl) methane was added by cannula with cooling. After reacting at room temperature for 2 hours, lithium chloride produced was removed and the solution was concentrated to obtain orange crystals. Yield 0.8 g. The physical properties of this compound are shown below. The IR spectrum was measured using the KBr method, and the ¹ H-NMR spectrum was measured using CDCl ₃ as a solvent. Also Mas
The s-spectrum was measured by the direct introduction method. Elemental _{analysis: (C 25 H 32 ZrCl 2} ) Calculated (%): C; 60.78, H; 6.53 Found (%): C; 60.93, H; 6.60 IR spectrum: FIG. It is shown in FIG. NMR spectrum: shown in FIG. Mass spectrum: shown in FIG.

Example 2 [Polymerization] 1.5 liters of sulfur sufficiently purged with nitrogen
300 ml of purified toluene was placed in a US autoclave. Methylaluminoxane manufactured by Tosoh Akzo (2. per aluminum)
7M) and 0.02 mmol of isopropylidene (3-tbutylcyclopentadienyl) (3-tbutylindenyl) zirconium dichloride are sequentially added,
Cooled to 3 ° C. Then, 2 mol of propylene was added and 1
After the polymerization was carried out for a period of time, the catalyst component was decomposed with methanol, and the resulting polypropylene was dried. As a result, 37 g of high isotactic polypropylene was obtained. The molecular weight of the polymer was 108,000.

Example 3 [Copolymerization] 300 ml of purified toluene was placed in a SUS autoclave having an internal volume of 1.5 liter and sufficiently purged with nitrogen. 15 ml of methylaluminoxane (2.7 M per aluminum) manufactured by Tosoh Akzo and 0.02 mmol of isopropylidene (3-tbutylcyclopentadienyl) (3-tbutylindenyl) zirconium dichloride are sequentially added and cooled to 3 ° C. did. Then, 2 mol of propylene was added, and polymerization was carried out for 1 hour at an ethylene pressure of 1 kg / cm ^2. After the reaction, the catalyst component was decomposed with methanol and the obtained polypropylene was dried. As a result, 37 g of EPR having good randomness was obtained. The molecular weight of the polymer was 150,000.

[0014]

According to the present invention, a novel zirconium compound having a bridging ligand having an asymmetric substituent can be obtained. If these zirconium compounds are used as olefin polymerization catalyst components in olefin polymerization, stereospecific polymers can be produced efficiently.

[Brief description of the drawings]

FIG. 1 is an IR spectrum of the zirconium compound of the present invention.

FIG. 2 is an NMR spectrum of the zirconium compound of the present invention.

FIG. 3 is a Mass spectrum of the zirconium compound of the present invention.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-3-21607 (JP, A) JP-A-3-1000004 (JP, A) British Patent Application Publication 2241244 (GB, A) Stud. Surf. Sci. Cat al. (1990), 56 (Catal. Olefin Polym.) Pp501-15 "Propylene Polymerization by Stereorigid Metallolysis Catalysts" New J. Biol. Chem. , 1990, 14, pp 499-533 (58) Fields investigated (Int. Cl. ⁷ , DB name) C07F 17/00 C07F 7/00

Claims (1)

(57) [Claims] 1. A non-C2 symmetric zirconium compound having an asymmetric ligand represented by the general formula (1). Embedded image [In the formula (1), X ¹ and X ² may be the same or different and each represent a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, an alkylsilyl group, or a halogen atom.
R ¹ represents a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms or an alkylsilyl group, and one of R ² and R ³ represents a hydrocarbon group or an alkylsilyl group having 1 to 10 carbon atoms, The other means a hydrogen atom. R ⁴ represents a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms or an alkylsilyl group. ]